During their 39 days on the run, the pair was caught on surveillance video at an Oklahoma Walmart and police say they stayed at cheap motels with one bed.

Cummins was Thomas' forensics teacher at their high school in Maury County, south of Nashville. Police say he had been researching teen marriages and was seen kissing Thomas at the school earlier in the year.

Quinn says she spoke to Cummins three times over the weekend.

“He's done this horrible thing, that he has to pay for,” she told NBC News. “But he's still my brother and I love him.”

"There is no doubt that she suffered severe emotional trauma and that her process of recovery is only just beginning," he said Friday.

Speaking to reporters in California Friday, Siskiyou County Sheriff Jon Lopey said Cummins was cooperative in the arrest and that Thomas' emotions indicated they had a "relationship."

"I can tell you that her mood was kind of escalated ... you know sometimes she was emotional, you know it was a very traumatic experience for her," Lopey said. "It was kind of a roller coaster of emotions for her."